I will not even presume to talk about sons, because I do not have one. I believe that with a son it is an entirely different dynamic.
I will just put across some insight that I have gleaned along the way. It was not premeditated, or even contrived. Its something that just worked for me. I hope someone can learn from it - and be able to have the same joy I have everyday of having a daughter for a best friend.
For one thing, never get involved in your child's life, especially after she hits teenage. Sounds terrible, but think about it. I have seen too many mothers trying to ensure that their daughters have the perfect life. They will fight the fights, direct every move. Well-meaning of course, but severely damaging to the relationship. The child is her own person. She has, and always will have, her own world. You do not belong there. Her friends, music, even studies, are in a realm that you have left; yours was in a different time - and in all probability a different place too! Oh yes, she belongs in your world. Do not force yourself into a door that never really was yours to open. The only door you can open is to YOUR own life. You may not belong in that new domain she has, but she of course belongs in yours. Do not close that to her. Let your child be a part of your space. Don't ask about her friends, tell her about yours. Do not try and inveigle an invitation to her parties, let her come with you to yours. Do not badger her about her dreams - they are yet nascent. Tell her about yours, both the shattered and the burgeoning. The capital of experiences she will build by learning through your trials and successes will help her through life.
Another thing I have learnt (the easy way - by just listening to my daughter!). Time is important. Not its passing, or its utilization. Your time with her. A lot of time simply wasted in 'quality time together', 'learning time,' 'bonding time'. She does not need that! She just needs you to watch that horrendous movie with her (even if all you do is mindlessly criticize whole time!) Or share a cupcake( or two) with her. Simply, just that.
Do not misinterpret the fallback that I am advocating as a lack of responsibility. You have to be there - always, with the smile and the hug of course, but also with the stern eye and the big lecture. I am not going to talk of morals, ethics or principles - because it is what you have that she will pick up - whether you like it or not. And as she grows she may just as well discard yours for her own!
Just be there, accepting, but non-intrusive, and then step back and let her take wing. You will delight in the individual she becomes. It is simple wisdom I wanted to share. But then, is wisdom ever simple?